High Cooling Power, Large Sample Space Cryostat
System: DRY ICE 1K
Customer: University of Bristol
Temperature Range: 1K - 300K
Cooling Power: 230mW @ 1.0K
Hold time: Continuous flow
Sample Space: 25cm x 25cm x 40cm
Bristol University had a requirement to be able to achieve sub 1.0K in order to optimise the efficiency of the single-photon detectors whilst simultaneously coping with the heat produced by optical components of several hundred mW. This would allow them to begin experiments with complete optical quantum computing circuits. This design built on a previous lower cooling power system supplied to MIT and once broke the world record for the lowest continous temperature achieved in a dry Helium-4 system.
The cryostat is fully insulated and has an Aluminium radiation shield which is thermally linked to the 1st stage of the cold head that sits at approximately 50K. The cryostat vacuum, super insulation and radiation shield all minimise the conduction and radiation heat load on to the sample space. The 1K pot and sample platform form an integral part of the cryostat and uses the same outer vacuum space that is used for the cryostat. A 1K pot system is utilised to create a volume of liquid Helium that is pumped on via the large Roots pump to create the low temperature stage. A Calibrated 0.3K Cernox and heater are wired onto the 1K Plate.
The cold head sits inside a cooling sock. (The design minimises any mechanical link to the cryostat and also means that the cold head can be removed without disassembling the system (for ease of service). The vibration is reduced further by the implementation of vibration damping bellows and a uniquely designed double support stand installed between the cryostat top plate and the cold head. The Helium within the closed loop is condensed by the 2nd stage of the cold-head into the 1K pot.
'I am a Lecturer in Quantum Engineering at the University of Bristol. My research aims at the integration of quantum photonic circuits with single-photon detectors in cryogenic environments. Our group defined a long-term strategic goal in 2013 and our system pre-requisites back then and we contacted many manufacturers of cryogenic systems. I have been working with ICEoxford for nearly 4 years and I am very glad with the outcomes.
ICEoxford are a unique company in the UK market; their philosophy brings together cutting-edge product development and a focus on research-led clients. Their expertise and knowledge of their clients’ needs grants them an excellent market position, but it is their client-focus that puts them ahead of the competition.
Quantum photonic computers will enable revolutionary solutions in the next decades. The requirements for operating such systems are complex and extreme. In the case of the systems developed at the University of Bristol, a key requirement is the dissipation of large amounts of power while keeping a very low temperature. Such conditions can be achieved in the cryostats developed by ICE Oxford and hardly anywhere else.
The high-cooling power cryostat ICE Oxford developed for us has been tailored for our needs from day one. They have offered us a unique solution, outperforming all other products currently in the market. The communication with their engineering team has been extremely satisfying, and has allowed us to understand better how the system works while preventing misconceptions. ICE Oxford have, therefore, contributed significantly to the development of quantum photonic instruments.
Please do not hesitate to contact me if you require any further information. Yours sincerely,
Jorge Barreto (2018)'